Analysis of structural variants in four African Cichlids highlights an association with developmental and immune related genes

African Lakes Cichlids are one of the most impressive example of adaptive radiation. Independently in Lake Victoria, Tanganyika, and Malawi, several hundreds of species arose within the last 10 million to 100,000 years. Whereas most analyses in Cichlids focused on nucleotide substitutions across species to investigate the genetic bases of this explosive radiation, to date, no study has investigated the contribution of structural variants (SVs) to speciation events (through a reduction of gene flow) and adaptation to different ecological niches. Here, we annotate and characterize the repertoires and evolutionary potential of different SV classes (deletion, duplication, inversion, insertions and translocations) in five Cichlid species (Haplochromis burtoni, Metriaclima zebra, Neolamprologus brichardi, Pundamilia nyererei and Oreochromis niloticus). We investigate the patterns of gain/loss across the phylogeny for each SV type enabling the identification of both lineage specific events and a set of conserved SVs, common to all four species in the radiation. Both deletion and inversion events show a significant overlap with SINE elements, while inversions additionally show a limited, but significant association with DNA transposons. Inverted regions are enriched for genes regulating behaviour, or involved in skeletal and visual system development. We also find that duplicated regions show enrichment for genes associated with “antigen processing and presentation” (GO:0019882) and other immune related categories. Altogether, we provide the first, comprehensive overview of rearrangement evolution in East African Cichlids, and some initial insights into their possible contribution to adaptation.

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Author Penso-Dolfin, Luca
Last Updated November 20, 2019, 16:43 (UTC)
Created August 1, 2019, 10:28 (UTC)
Article Host Type publisher
Article Is Open Access true
Article License Type cc-by-nc-nd
Article Version Type publishedVersion
Citation Report https://scite.ai/reports/10.1101/473710
DOI 10.1101/473710
Date Last Updated 2019-07-15T14:50:21.634309
Evidence open (via page says license)
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Journal Is Open Access false
Open Access Status hybrid
PDF URL https://www.biorxiv.org/content/biorxiv/early/2018/11/24/473710.full.pdf
Publisher URL https://doi.org/10.1101/473710